Magnetic data card servo writer

ABSTRACT

This invention discloses a magnetic servo writer. The magnetic servo writer includes a magnetic pickup head for rotationally moving over and writing servo data in a magnetic flat data-storage medium. The magnetic servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The magnetic servo writer further includes a control circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a servo pattern layout circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium with predefined servo patterns. The magnetic servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on the magnetic flat data-storage medium. The magnetic servo writer further includes a fixed index and clock track circuit for providing a fix index and a clock signal for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a head move circuit for controlling a movement of the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a medium movement circuit for controlling a linear movement of the magnetic flat data-storage medium for writing the servo data on the magnetic flat data-storage medium.

[0001] This Application is a Continuous Prosecution Application (CPA) ofa pending application Ser. No. 09/289,427 filed on Apr. 9, 1999.application Ser. No. 09/287,427 is a Continuation-in-Part (CIP) FormalApplication claims a Priority Date of Apr. 9, 1998, benefited from apreviously filed Provisional Application No. 60/081,257 by the sameApplicants of this Application.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to systems and method forreading data from and writing data to data storage medium by employingthe magnetic recording technology. More particularly, this invention isrelated to an improved magnetic data access system. The data accesssystem is implemented in a portable data card drive device and in a highspeed subsystem for reading data from and writing data to a magneticdata card which has a novel data track configuration for storing datawith uniform density. Data can be stored for user applications orrelated to application system configurations.

[0004] 2. Description of the Prior Art

[0005] Conventional technology of reading-writing data on concentriccircular data tracks often presents a problem that the data-bit densityvaries between the outer tracks and the inner tracks. The variable bitdensity in data storage is due to a geometrical factor that the outerdata tracks are much longer in length than the inner tracks. A commonpractice is to form the inner tracks with a capacity to store the databit at a higher bit density. A more complicate servo control systemimplemented with more complex signal-processing algorithms is requireddue to the variations of data storage density between different datatracks. Additionally, by varying the data storage density from the innertracks toward the outside tracks, the data transfer rate is also changedin accessing data from the inner tracks then outside tracks. Suchvariation may also cause difficulties and complications in processingthe data. Higher error rates may incur due to these variations betweenthe inner tracks and the outer tracks.

[0006] Therefore, a need still exists for an improved data-card drivesystem to overcome the aforementioned difficulties encountered in theprior art. Specifically, this storage card drive system must provide auniform density for data storage and a data-card drive system to accessthe data-storage card. Furthermore, it would be desirable that thissystem is portable and is also provided with several standardized sizesfor processing standardized data-storage cards.

SUMMARY OF THE PRESENT INVENTION

[0007] Therefore, an object of the present invention is to provide adata storage-card drive system with a pickup head moving above thedata-storage card in rotational movement. The data read-write functionsare enabled only for arc-segments of the rotational movement such thatthe data tracks are arranged as plurality of parallel arcs, e.g.,half-circles, to overcome the aforementioned difficulties andlimitations encountered in the prior art.

[0008] Specifically, it is an object of the present invention to providea data-storage card drive system with a pickup head driven by a motor,e.g., a brushless motor, to rotate over the data-storage card with therotation axis perpendicular to the card surface. The motor is mounted ona carriage for making horizontal movement along a longitudinal directionof the data card. The position of the pickup head is thenservo-controlled by moving the carriage and the motor while the datastorage card either stays at a fixed position or only pickup head isrotating and the card is making horizontal linear movements.

[0009] Another object of the present invention is to provide adata-storage card drive system for performing the data access tasks overa data storage medium surface, which has uniform data storage density. Anew configuration of data-tracks formed as parallel arc or arc-segments,e.g., semi-circular data track, is implemented such that all data trackshave substantially the same length for data storage and the data bitsare stored with uniform density.

[0010] Another object of the present invention is to provide adata-storage card drive device implemented with a subsystem providedwith local memory storage for conveniently interface with personalcomputers or peripheral devices to achieve higher speed operations.

[0011] Briefly, in a preferred embodiment, the present inventiondiscloses a magnetic servo writer. The magnetic servo writer includes amagnetic pickup head for rotationally moving over and writing servo datain a magnetic flat data-storage medium. The magnetic servo writerfurther includes a clock head for providing clock signals to the pickuphead and to write clock signals in the clock disk. The magnetic servowriter further includes a control circuit for controlling the magneticpickup head for writing the servo data on the magnetic flat data-storagemedium. The magnetic servo writer further includes a servo patternlayout circuit for controlling the magnetic pickup head for writing theservo data on the magnetic flat data-storage medium with predefinedservo patterns. The magnetic servo writer further includes a derivedindex control circuit for deriving indices from a fixed index providedon the magnetic flat data-storage medium. The magnetic servo writerfurther includes a fixed index and clock track circuit for providing afix index and a clock signal for controlling the magnetic pickup headfor writing the servo data on the magnetic flat data-storage medium. Themagnetic servo writer further includes a head move circuit forcontrolling a movement of the magnetic pickup head for writing the servodata on the magnetic flat data-storage medium. The magnetic servo writerfurther includes a medium movement circuit for controlling a linearmovement of the magnetic flat data-storage medium for writing the servodata on the magnetic flat data-storage medium.

[0012] These and other objects and advantages of the present inventionwill no doubt become obvious to those of ordinary skill in the art afterhaving read the following detailed description of the preferredembodiment which is illustrated in the various drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIGS. 1A and 1B shows a cross sectional view and a top viewrespectively of a data card drive system of this invention;

[0014]FIGS. 1C and 1D are cross sectional views for showing the detailsof the motor rack mounting and the head loading/unloading assembly;

[0015]FIG. 1E shows a perspective view of the pickup head and the wireswinding configuration serving as read/write data signal transformer;

[0016]FIGS. 1F and 1G show the top view and cross sectional viewrespectively of a magnetic servo writer of this invention;

[0017]FIGS. 2A to 2C are respectively a top view, a cross sectional viewand a bottom view of a data storage card with data tracks formed forstoring bits with uniform density in each of these data tracks;

[0018]FIG. 2D to 2Q show the top views of the data storage card of thisinvention where the data tracks can be arranged in arc-segments ofdifferent shapes, sizes, and facing different directions;

[0019]FIGS. 3A and 3B are a perspective view and a cross sectional viewrespectively of a data card storage box;

[0020]FIG. 4 is a functional block diagram of a subsystem of thisinvention includes a data card drive device of FIGS. 1A to 1C forreading/writing data storage card of FIGS. 2A to 2C;

[0021]FIGS. 5A and 5B show the data tracks on a magnetic data card withdata tracks for writing servo data thereon;

[0022]FIG. 5C shows an exemplary pattern of servo data written onto adata track;

[0023]FIG. 5D shows the position indexes for servo control; and

[0024]FIG. 5E is a functional block diagram to illustrate the controllogic implementation of a servo writer of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025]FIGS. 1A and 1B show a cross sectional view and a top viewrespectively of a data-card drive 100 of the present invention. Thedata-card drive 100 can be configured for reading and writing data-cardsof different sizes, e.g., a PCMCIA type card or common credit card size.The data-card can also be of different shapes such as a square, arectangular, a circular disk, or a card with straight and parabolicedges or different types of arc-edges. The data-card drive 100 includesa motor 110, e.g., a DC brushless motor. The motor 110 is provided tooperate at a low speed to conserve battery power, at high speeds toachieve fast data access time. The motor 110 is further provided tofunction at two different modes, i.e., a sleep mode when not beingdeployed, and a wake up mode for normal data access operations. Themotor 110 is mounted on a carriage 115 with a pickup head assemblymounted to the motor rotating shaft assembly. Half of a magnetictransformer, 120-1 which can either being a ring type, a round-disktype, or other geometrical shapes, is mounted onto the motor rotatingshaft assembly, the other half of the magnetic transformer 120-2 ofsimilar configuration is mounted to the fixed part of motor assembly.Signal wires 130 form head are soldered onto the rotating half of thetransformer 120-1 with the soldering pad 125, that can also be a springpressed connection, for transmitting the read/write signals via themagnetic transformer 120. The magnetic transformer 120-1 and thesoldering pad 125 are covered by a magnetic flux shield plate 135 forshielding the magnetic flux generated by the magnetic transformer toprevent DC erase of data. A ground spring 140 is applied to perform thefunction of dissipating electric static discharges. Optionally, abrake-magnet 145 is provided to fix the “parking” position of the motor110 in the sleep or power off mode during the time when there is no dataaccess activities.

[0026] A read/write head 150 is mounted via an extended head-arm 152 tothe brushless motor 110 via a head-arm mounting assembly mounting holes155 to the head carriage 115. A head loading/unloading arm 160 ismounted on the base-plate 170. The loading/unloading arm 160 presses tothe head-arm 152 at the unload position at a drive-device power-offmode. The loading/unloading arm 160 is removed from the head-arm 152when a data card 180 is loaded and the power for the drive device isturned on.

[0027] In order to assist a smooth loading of the data card 180 into thedrive device 100, a card guide plate 185 is provided. The data-carddrive system 100 further includes one or several data card pins 190 toengage and fix the position of the data card 180 when the data card 180reaches a designated operational position. The data card pins 190increases the compatibility and interchangeability of different types ofdata cards for data access operations using this data card drive system100. The drive system 100 further includes an on/off switch 195, whichis turned on when the data card 180 reaches its final position.

[0028] The brushless motor 110 is mounted onto a motor-rack mount 200with a rack 205 and a pinion 210. A step motor 220 is employed tocontrol the linear movement of the motor 110 or the movement of the datacard 180. The drive device 100 further includes a LCD display 230 toindicate the track position of the head 150 in reading or writing ofdata onto the data card 180. Mounted on the base plate 170 is a printedcircuit board 240, which supports a track locator switch 245. Theprinted circuit board 240 further supports various kinds of circuits forperforming the functions of control and data access. These circuitsincludes head tracking circuit 250, IC preamplifier 255, headloading/unloading circuits, disable/enable read-write function circuit,servo control integrated circuit (IC), motor control IC, data separatorIC, ADI interface IC, USB interface IC, PCMCIA interface IC, USBconnector, PCMCIA connector, and other circuits required for controllingand operating the data card drive system. FIGS. 1C and 1D are crosssectional views for showing the details of the rack 205, the pinion 210,and the head loading and unloading assembly 160 to lift the head whenthe drive device 100 is turned off. A head arm lifter 103 has a wiretype hook 103A positioned above the pickup head arm 152. The sliding ofthe head arm lifter 103 with the wire type hook 103A along the motorshaft assembly can lift or lower the pickup head arm 152 and in turnlift or lower the pickup head 150. The pickup head arm 152 is rotatingwith the motor shaft and the pickup head 150. Regardless of where thepickup head 150 when the rotational movement stops, the arm 152 canalways engage into the head lifter 103 slot and sliding the head lifter103 along the motor shaft.

[0029] The drive device 100 as described above is also provided with anoption to perform the functions of a servo writer. A novel servo writeris disclosed in this invention which can be manufactured with simplifiedmanufacturing processes. The servo writer includes a storage cardloading assembly that is structured similarly to a card guide 185 of thedevice 100. The storage card can be inserted horizontally inserted fordirect contact with the pickup head 150. Or, depending on specificapplication, the data storage card can be inserted from a vertical slotopening and then flip over for contact with the pickup head. In writingthe servo data, the pickup head 150 is rotating along different datatracks. The pickup head is moved to different tracks during theoperation of writing servo data by either moving the head/motor assemblymounted on the shaft or by keeping the head/motor assembly stationarywhile horizontally moving the data storage card. The magnetictransformer is employed in writing the servo data onto different datatracks where the cables are arranged without being twisted when thepickup head is making rotational movement.

[0030]FIGS. 1F and 1G are a top view and a cross sectional view of apreferred embodiment of a data-card servo writer system 100′, which hasa clock head 105 connected to a clock disk 107. The clock disk 107 isdisposed below the magnetic data card 180 and de-coupled from the datacard 180. The motor drives the pickup head 150 also drives the clockdisk 107. The clock disk can be rotated while the clock head 105 isfixed and stationary and mounted on the frame assembly of the servowriter system 100′. The clock head 105 is employed to write clocksignals, e.g., a binary bit 1 for the whole cycle. All of the data bitson the entire data track of the clock track are binary bit “1 ”. Then, apulse is stopped to write a binary bit “0” to provide that “0” as indexwhile using all the bit “1” for timing to format the card. Read andwrite signals of the clock head 105 is transmitted through wires to theclock disk 107 formed on a printed circuit board. The clock head 105 isemployed to write the clock signals onto the magnetic clock disk and toread back the signals. The clock signals read back from the magneticclock disk are used as timing signals to format the card to include theservo patterns to be further described below. Once the magneticdata-card 180 is formatted by the servo-writer system 100′, it is readyfor data read/write operations by applying a regular magnetic data-carddrive system as that shown in FIGS. 1A to 1E. The formatted sectors onthe magnetic data-card 180 are also write-protected to preventincidental writing over these segments. (Do we need to describe writeprotection in some details in order to claim this feature?)

[0031] According to FIGS. 1A, 1B, 1C and 1D and above descriptions, thepresent invention discloses a data-card drive system 100 the presentinvention includes a magnetic data-card drive system. The drive systemincludes a magnetic pickup head for rotationally moving over andaccessing data stored in the magnetic data-card. In a preferredembodiment, the magnetic pickup head is provided for reading data fromand writing data to the magnetic data card. In another preferredembodiment, the magnetic pickup head is provided for accessing data oversubstantially one-half of the rotational movement. In another preferredembodiment, the magnetic pickup head is provided for accessing data overseveral arc-segments during the rotational movement. In anotherpreferred embodiment, the magnetic pickup head is provided for rotatingin a single rotational direction. In another preferred embodiment, themagnetic pickup head is provided for rotating in clockwise andcounterclockwise directions. In another preferred embodiment, themagnetic pickup head is provided for rotating over arc segment havingradius smaller than half-width of the magnetic data card. In anotherpreferred embodiment, the magnetic pickup head is provided for rotatingover an arc segment having a radius greater than half-width of themagnetic data card. In another preferred embodiment, the magnetic pickuphead is provided as a removable and replaceable module. In anotherpreferred embodiment, the magnetic pickup head is provided for accessingdata by contacting the magnetic data card. In another preferredembodiment, the magnetic pickup head is provided for accessing data byrotating at a distance above the magnetic data card. In anotherpreferred embodiment, the magnetic data-card drive system of furtherincludes a motor that has a rotating shaft for mounting and rotating themagnetic pickup head. In another preferred embodiment, the magneticpickup head further includes a data signal transformer for transforminga data signal through data signal induced changes of magnetic flux.

[0032]FIG. 1E is a perspective view of an alternate configuration of adata signal transformer 120′. The data signal wires 130-1 connected tothe pickup head 150′ supported on the arm 152′ for the pickup head 150′are first winding around an inner signal transforming cylinder 122′,which rotates with the rotation shaft or the motor 110′. A stationaryhollow pipe 124′ is placed around the inner signal-transforming cylinder122′. A set of signal transforming wires wrap around this stationaryhollow pipe 124′. For read/write data, an electric signal representing abinary bit can be transferred from a pickup head 150′ through the wires135′ to the wires wrapping around the inner signal-transforming cylinder122′. The electric signals, typically an electric pulse, transferred tothe wires around the inner cylinder 122′ can be detected with variationsof electromagnetic field by a set of wires wrapping around thestationary hollow pipe 124′. Similarly, the data signal for the pickuphead 150′ can also be provided to the wires wrapping around thestationary hollow pipe 124′ as electric pulses and detected by the wireswrapping around the inner signal transforming cylinder 122′ for transferto the pickup head 150′. The wires around the inner and outercylindrical pipes function as inductive coils serving the function ofdata signal transformation.

[0033]FIGS. 2A to 2C are respectively a top view, a cross sectionalview, and a bottom view of a data card 180 of the present invention. Thedata card 180 is formed on a substrate plate 250. The substrate-plate250 for magnetic recording is composed of non-magnetizable materialswith a flat surface, e.g., a plastic or glass substrate plate. Formagnetic recording, a magnetizable material can also be employed to formthe substrate plate 250. The substrate plate 250 is then coated with athin layer of recording medium on one side or both sides. For magneticrecording, the coating are formed by magnetic particles coated onone-side or both sides of the substrate plate 250. The magnetic coatingcan be directly on the surface of the substrate plate 250 or on a Mylartype of material with adhesive layer for attaching to the substrateplate 250. For magnetic recording the recording medium layer can beformed by a process similar to that of a magnetic compact-disk (CD),CDR, LD, or digital video display (DVD) disks. The data card 180 can beformed with standardized sizes, e.g., PCMCIA standard sizes or standardcredit card sizes, and has round or elongated holes 260 for fixing thecard at pre-designated positions to initialize a data access operation.The holes 260 are fitted to the pins 190 to provide the self-centeringand locking functions. The data storage card 280 can therefore berepeatedly placed at a pre-designated position with reliable accuracy.The data card 180 is provided with a plurality of data tracks 270 forstoring data bit on each track. Each of these data tracks is formed assubstantially an arc or arc-segments track. The data tracks 270 aresubstantially of a same length and are substantially parallel to eachother. The data tracks 270 are formatted to include multiple sectors.One or several of these sectors can be flexibly employed to provideservo data for the purpose of identifying track locations to enhancesector seeking during a data-access operation. The servo-data areprovided in sectors near both ends of the arc or arc-segments datatracks 270 as shown in FIG. 2A. For the purpose of more preciselypositioning the data card 180 in a drive device, a notch 275 is formednear the inner end of the data card 180. With the notch 275, the datacard 180 is more conveniently placed into the drive device fitted to theinitial card position ready for operation relative to the position ofthe pickup head 150. The data card 180 is then covered by a protectivecoating 280 preventing damages from exposure to water, dust and otherforeign particles introduced through the daily operational environment.The data card 180 is then stored in a data card envelop 290 for storageand shipment. The data storage tracks of the data card may contain userapplication and system configuration data. The recorded data can beupdated in the field. Application system can either encrypt or decryptthe recorded data. Application system can also change the configurationsuch as set and reset the write protection, the password and otherfeatures related to the data-access operations.

[0034]FIGS. 2D to 2Q are top views of the data storage card 180 forshowing different configuration of the data tracks 270. The data tracks270-1 can be parallel arcs facing opposite directions on either side ofthe data card 180 as shown in FIG. 2D. Alternately, each of the datatracks 270-1 as parallel arc as that shown in FIG. 2D can be partitionedinto a plurality of arc-segment 270-2 as that shown in FIG. 2E. In asimilar manner, the data tracks can be parallel arcs 270-3 formed overthe entire data card area as that shown in FIG. 2F. Furthermore, each ofthe parallel arcs 270-3 of FIG. 2F can also be partitioned into aplurality of arc segments 270-4 as that shown in FIG. 2G.

[0035] According to FIGS. 1 to 2, this invention discloses a magneticdata-storage card. The magnetic data-storage card includes a magneticdata-storage medium layer supported on the card. The data-storage mediumlayer includes a plurality of data storage tracks for storing datatherein. Each of the tracks comprising at least an arc-segment whereineach of the data storage track being substantially parallel to aneighboring track. In a preferred embodiment, each of the arc-segmentsare substantially of a same segment length. In a preferred embodiment,the data-storage tracks further storing servo control data. In apreferred embodiment, the data-storage tracks further storing theservo-control data at a substantially same relative position on thedata-storage tracks. In another preferred embodiment, the data-storagetracks further storing the servo-control data near edges of thedata-storage card on the data-storage tracks. In another preferredembodiment, each of the data-storage tracks is substantially asemicircular arc-segment. In another preferred embodiment, each of thedata-storage tracks includes several arc segments. In another preferredembodiment, the magnetic data-storage card further includesself-positioning guiding means for guiding the card to a loadingposition when inserted into a data card drive device. In anotherpreferred embodiment, the magnetic data storage card having a first sideand a second side and the data-storage tracks are disposed on the firstand second sides. In another preferred embodiment, the magnetic datastorage further includes a card jacket for storing the data storagecard.

[0036] Furthermore, this invention provides a new method for storingdata in a magnetic data-storage card. The method includes the steps ofa) providing a magnetic data-storage medium layer supported on thedata-storage card. And, b) forming in the data-storage medium layer aplurality of data storage tracks for storing data therein by formingeach of the tracks to include at least an arc-segment and each of thedata storage tracks substantially parallel to a neighboring track. In apreferred embodiment, the step of forming the data'storage tracks as arcsegments is a step of forming each of the arc segments substantially ofa same segment length. In another preferred embodiment, the methodfurther includes a step of storing servo control data in thedata-storage tracks. In another preferred embodiment, the step ofstoring the servo-control data is a step of storing the servo-controldata at a substantially same relative position on the data-storagetracks. In another preferred embodiment, the step of storing theservo-control data is a step of storing the servo-control data nearedges of the data-storage card on the data-storage tracks. In anotherpreferred embodiment, the step of forming the data-storage to include atleast an arc segment is a step of forming each of the data-storagetracks substantially as a semicircular arc-segment. In another preferredembodiment, the step of forming the data-storage to include at least anarc segment is a step of forming each of the data-storage tracks toinclude several arc segments. In another preferred embodiment, themethod further includes a step of providing a self-positioning guidingmeans for guiding the magnetic data-storage card to a loading positionwhen inserted into a data card drive device. In another preferredembodiment, the step of providing a magnetic data-storage medium layersupported on the card is a step of providing the magnetic data storagecard to include a first side and a second side. And, the step of formingin the data-storage medium layer a plurality of data storage tracks is astep of forming the data-storage tracks on the first and second sides.In another preferred embodiment, the method further includes a step ofproviding a card jacket for storing the data storage card.

[0037]FIGS. 3A and 3B are a perspective view and a side view of a datacard storage rack 295 for storing a plurality of data card 180 therein.The data card storage rack 295 as shown can be formed as partitionedstorage box with each compartment ready to receive one data card 180.The data card storage rack 295 can function as a portable digital cameraalbum or a backup data store for long term data storage.

[0038]FIG. 4 shows a subsystem 300 of this invention that includes adata card drive device 310 identical with the drive device 100 describedabove according to FIGS. 1A to 1C. The disk drive device 310 performsthe data access tasks on a data storage card 320 identical to the datacard 180 described above according to FIGS. 2A to 2C. The subsystem 300further includes a local memory 330, which can be a DRAM or SRAM memorydevice connected to the disk drive device 310. The data stored in datacard 320 can be first down loaded to the memory device 330 through adata bus for data storage. The subsystem 300 further includes a functioncontrol panel 340 to allow a user to control the subsystem startup,shutdown, save, update, and duplication of the data stored in the card.The subsystem 300 is further provided with a connection terminal 350 forconnection to a personal computer, a printer, a scanner or otherperipheral devices for operation together with the drive devicesubsystem 300. A power supply 360 is employed and connected to thesubsystem 300 to provide power necessary for operating the drive device310, the memory 340 and the control panel 330.

[0039] Referring to FIGS. 5A to 5C for examples to illustrate the servosignal patterns written onto the arc segments of the data-storage trackson a data storage card. FIG. 5A shows the data storage tracks as arcsegments, which may or may not be circular arcs. The servo writer mustwrite servo signals on these data-tracks. Referring to FIG. 5B, thesurface area of the magnetic data-storage card is divided into zones Ato F according to clockwise direction. The servo writer should bedisabled for Zones A, B, D, and E since these zones are not part of thedata tracks. The servo writer must also be disabled in zone E becausethe servo data may be overlapped and create confusions in the process ofpickup head location and track determinations. It is obvious theconventional servo writer and control mechanisms can no longer beemployed for the magnetic data card drive system of this invention.

[0040] As shown in FIG. 5A, the length of the data tracks depends on thesize and dimensions of the data card. Each data track is divided into Nsegments and each segment is provided to contain pre-defined servo data,prerecorded data and/or definitions of area for data records. FIG. 5C isan example of the data arrangements across the tracks of such segment.The total number of data tracks N is determined by the requirements ofthe accuracy of the mechanical and electrical responses. The servo datashown in FIG. 5C can provide the track profile, the location of thetrack and the relative location of signal pickup head to a data trackalong a track.

[0041] Referring to the details of data arrangement shown in FIG. 5C,the signals generated from data bit-patterns A and B are for positiondetermination. Each data track has a half data slots provided for A andhalf of the slots provided for B. The balance of A and B detected by thepickup head and the track location determination circuits provideindications that the pickup head is travelling in the center of the datatrack. Table 1 shows the data sample employed for providing servo datafor track and location determinations as the pickup head is travellingover the surface of the magnetic data storage card. TABLE 1 Example ofPartial Servo Segment Data SYNC 1010101010101010 ADM 1000000010000001 STIDX 11 for First Segment 00 for other segments ED IDX 11 for lastsegment 00 for other segments A 0000001100000000 B 0000000000000011

[0042] Referring to FIG. 5D, since the data track can only bearc-segments as that shown FIG. 5A, the servo writer must start and stopto layout patterns at pre-determined locations. An index is used as areference point at a fixed location on the magnetic data-storage card.The starting point SX and the stopping position EX of the servo data arederived from the reference point IX as shown in FIG. 5D. A servo controlcircuit is employed to enable and disable the pattern layout process andto move the magnetic pickup head and the flat data-storage medium, i.e.,the magnetic data storage card by using the feedback by detecting thesethree indices. An exemplary functional block diagram for implementingthe control logic in the servo control circuit is shown in FIG. 5E.

[0043] According to FIGS. 5A to 5E, this invention discloses a magneticservo writer. The magnetic servo writer includes a magnetic pickup headfor rotationally moving over and writing servo data in a magnetic flatdata-storage medium. The magnetic servo writer further includes a clockhead for providing clock signals to the pickup head and to write clacksignals in the clock disk. The magnetic pickup head is provided forwriting SYNC data for synchronization of read channel, and ADM data forproviding address mark for indicating data-types following the ADM data.The magnetic pickup head is provided for writing ST IDX data forindicating a first valid data segment, ED IDX data for indicating a lastvalid data segment, and GRAY CODE data for indicating a head number, asector number, and a track number. Furthermore, the magnetic pickup headis provided for writing SERVO POS data for indicating a relativeposition of signal head to a data track, DATA & GAP data for indicatingan area for containing pre-recorded data. In a preferred embodiment, themagnetic pickup head is provided for writing index data for indicating avalid data track segment.

[0044] According to the functional block diagram of FIG. 5E and FIGS. 1Fand 1G, a magnetic servo writer is disclosed in this invention. Themagnetic servo writer includes a magnetic pickup head for rotationallymoving over and writing servo data in a magnetic flat data-storagemedium. The magnetic servo writer further includes a clock head forproviding clock signals to the clock head and to write clock signals inthe magnetic clock disk. The magnetic servo writer further includes acontrol circuit for controlling the magnetic pickup head for writing theservo data on the magnetic flat data-storage medium. The magnetic servowriter further includes a servo pattern layout circuit for controllingthe magnetic pickup head for writing the servo data on the magnetic flatdata-storage medium with predefined servo patterns. The magnetic servowriter further includes a derived index control circuit for derivingindices from a fixed index provided on the magnetic flat data-storagemedium. The magnetic servo writer further includes a fixed index andclock track circuit for providing a fix index and a clock signal forcontrolling the magnetic pickup head for writing the servo data on themagnetic flat data-storage medium. The magnetic servo writer furtherincludes a head move circuit for controlling a movement of the magneticpickup head for writing the servo data on the magnetic flat data-storagemedium. The magnetic servo writer further includes a medium movementcircuit for controlling a linear movement of the magnetic flatdata-storage medium for writing the servo data on the magnetic flatdata-storage medium.

[0045] Therefore, the present invention discloses a data storage-carddrive system with a pickup head moving above a data-storage card inrotational movement. The data read-write functions are enabled only foran arc segment, e.g., half-circle, or several arc segments of therotational movement. The data tracks are arranged as plurality ofparallel arcs, e.g., half-circles, or arc-segments with uniform data bitstorage density. Specifically, a pickup head is provided, which isdriven by a brushless motor to rotate over the data-storage card. Themotor is mounted on a carriage for making horizontal movement along alongitudinal direction of the data card. The position of the pickup headis then servo-controlled by moving the carriage and the brushless motorwhile the data storage card either stays at a fixed position or makingonly forward-backward movements. The difficulties and limitationsencountered in the prior art due to a non-uniform data storage densityamong different data tracks are resolved by this invention. Thetechnical difficulties caused by problems in loading/unloading of thepickup head to the recording medium, the transfer of read/write signalbetween the pickup head and the processing circuits, and the selfcentering of the data card in a data card drive device are also resolvedby this invention. Furthermore, the difficulty of positioning andlifting horizontal rotating pickup head parallel to a flat recordingsurface at any intermediate stop location to convert the signal from theflat card to parallel rotating pickup head to process circuit

[0046] Although the present invention has been described in terms of thepresently preferred embodiment, it is to be understood that suchdisclosure is not to be interpreted as limiting. Various alternationsand modifications will no doubt become apparent to those skilled in theart after reading the above disclosure. Accordingly, it is intended thatthe appended claims be interpreted as covering all alternations andmodifications as fall within the true spirit and scope of the invention.

We claim:
 1. A magnetic servo writer comprising: a rotating magneticpickup head for rotationally moving over and writing servo data in amagnetic flat data-storage medium; and a lateral movement means formoving said flat data-storage medium along lateral directionssubstantially perpendicular to a rotational axis of said rotating pickuphead.
 2. The magnetic servo writer of claim 1 wherein: said rotatingmagnetic pickup head is provided for writing SYNC data for read channelsynchronization.
 3. The magnetic servo writer of claim 1 wherein: saidrotating magnetic pickup head is provided for writing ADM data forproviding address mark for indicating data-types following said ADMdata.
 4. The magnetic servo writer of claim 1 wherein: said rotatingmagnetic pickup head is provided for writing ST IDX data for indicatinga first valid data segment.
 5. The magnetic servo writer of claim 1wherein: said rotating magnetic pickup head is provided for writing EDIDX data for indicating a last valid data segment.
 6. The magnetic servowriter of claim 1 wherein: said rotating magnetic pickup head isprovided for writing GRAY CODE data for indicating a head number, asector number, and a track number.
 7. The magnetic servo writer of claim1 wherein: said rotating magnetic pickup head is provided for writingSERVO POS data for indicating a relative position of said rotatingmagnetic pickup head to a data track.
 8. The magnetic servo writer ofclaim 1 wherein: said rotating magnetic pickup head is provided forwriting DATA & GAP data for indicating an area for containingpre-recorded data.
 9. The magnetic servo writer of claim 1 wherein: saidrotating magnetic pickup head is provided for writing index data forindicating a valid data track segment.
 10. The magnetic servo writer ofclaim 1 further comprising: a control circuit for controlling saidrotating magnetic pickup head for writing said servo data on saidmagnetic flat data-storage medium provided only to move along lateraldirections substantially perpendicular to a rotational axis of saidrotating pickup head.
 11. The magnetic servo writer of claim 1 furthercomprising: a servo pattern layout circuit for controlling said rotatingmagnetic pickup head for writing said servo data on said magnetic flatdata-storage medium with predefined servo patterns.
 12. The magneticservo writer of claim 1 further comprising: a derived index controlcircuit for deriving indices from a fixed index provided on saidmagnetic flat data-storage medium provided only to move along lateraldirections substantially perpendicular to a rotational axis of saidrotating pickup head.
 13. The magnetic servo writer of claim 1 furthercomprising: a fixed index and clock track circuit for providing a fixindex and a clock signal for controlling said rotating magnetic pickuphead for writing said servo data on said magnetic flat data-storagemedium provided only to move along lateral directions substantiallyperpendicular to a rotational axis of said rotating pickup head.
 14. Themagnetic servo writer of claim 1 further comprising: a head move circuitfor controlling a movement of said rotating magnetic pickup head forwriting said servo data on said magnetic flat data-storage mediumprovided only to move along lateral directions substantiallyperpendicular to a rotational axis of said rotating pickup head.
 15. Themagnetic servo writer of claim 1 further comprising: a medium movementcircuit for controlling a linear movement of said magnetic flatdata-storage medium along lateral directions substantially perpendicularto a rotational axis of said rotating pickup head for writing said servodata on said magnetic flat data-storage medium.